Equipment
Nikkor
400 F5.6 AIS
(left click on image to go to next image in series)
Introduced in 1973, this lens remained in production only a few years until replaced by a similarly sized lens with a gold band indicating that the front element contained ED glass. However, the lens above, according to the papers, actually contains fluorite crystal and special rare earth glass which has been multi coated. Take that! No wonder its production run was so short. The lens contains 5 elements in three groups.
Mechanically, the lens has a focus throw that is really long that makes it difficult to rapidly focus from close up to infinity. The built in lens hood and 360 degree rotating tripod collar were ahead of their time.
Optically, the lens is corrected for all three primary colors which makes it critically sharp for stationary subjects.
I have attached a pdf file of the front page of the papers that came with the lens which may clear up a few questions on the optical construction of the lens.